1. Field of the Present Invention
The present invention relates to an explosion-proof safety structure for column shape lithium battery, particularly relates to a structure design for assuring the safety in usage of a lithium battery which has multiple safety securing measurements such as circuit opening and pressure releasing.
2. Description of the Related Prior Art
As we all know, the secondary lithium battery has advantages of big capacity and light weight, which has become, up to date, the most popular one in the secondary battery market. However, while the secondary lithium battery is overcharged caused by charging too long, the electrolyte in the battery decomposes to cause a sudden rise of the battery internal temperature and the internal pressure increases accordingly, which consequently creates a risk of ignition or explosion. Though the conventional secondary lithium battery is installed with an explosion preventing mechanism, the explosion preventing mechanism is too thick so as to occupy too much space; therefore, the capacity of the conventional secondary lithium battery is not easy to upgrade. In addition, these explosion preventing mechanisms have disadvantages of manufacturing cost being too high and number of elements being too much and volume being too huge despite of their protecting function, which retards the development of high capacity lithium battery.
In view of the disadvantages of conventional lithium batteries, the present invention discloses an improvement on the explosion preventing structure which is safer, cheaper, and smaller after many times of testing.
The main purpose of the present invention is to provide an improvement for a safe and explosion preventing structure of a column shape lithium battery. The thin portion of the battery breaker sheet of the present invention breaks to cause an open charging circuit. While the internal pressure of the battery is too high, the safety valve damages to accomplish the purpose of releasing pressure. Meanwhile, the battery stops overcharging so as to prevent the ignition and gas explosion of the battery.